Summary: Beta thalassemia is an autosomal recessive disorder characterized by reduced (β+) or absent (β0) beta‐globin chain synthesis. In Lebanon it is the most predominant genetic defect. In this study we investigated the religious and geographic distribution of the β‐thalassemia mutations identified in Lebanon, and traced their precise origins. A total of 520 β‐globin chromosomes from patients of different religious and regional backgrounds was studied. Beta thalassemia mutations were identified using Amplification Refractory Mutation System (ARMS) PCR or direct gene sequencing.Six (IVS‐I‐110, IVS‐I‐1, IVS‐I‐6, IVS‐II‐1, cd 5 and the C>T substitution at cd 29) out of 20 β‐globin defects identified accounted for more than 86% of the total β‐thalassemia chromosomes. Sunni Muslims had the highest β‐thalassemia carrier rate and presented the greatest heterogeneity, with 16 different mutations. Shiite Muslims followed closely with 13 mutations, whereas Maronites represented 11.9% of all β‐thalassemic subjects and carried 7 different mutations. RFLP haplotype analysis showed that the observed genetic diversity originated from both new mutational events and gene flow from population migration. This study provides information about the types and distribution of β‐thalassemia mutations within each religious group and geographic region, which is essential for the implementation of screening and prevention programs.
The human diet has altered markedly during the past four decades, with the introduction of Trans hydrogenated fat, which extended the shelf-life of dietary oils and promoted a dramatic increase in elaidic acid (Trans-18.1) consumption. Food additives such as monosodium glutamate (MSG) and aspartame (ASP) were introduced to increase food palatability and reduce caloric intake. Nutrigenomics studies in small-animal models are an established platform for analyzing the interactions between various macro- and micronutrients. We therefore investigated the effects of changes in hepatic and adipose tissue gene expression induced by the food additives ASP, MSG or a combination of both additives in C57Bl/6 J mice fed a Trans fat-enriched diet. Hepatic and adipose tissue gene expression profiles, together with body characteristics, glucose parameters, serum hormone and lipid profiles were examined in C57Bl/6 J mice consuming one of the following four dietary regimens, commencing in utero via the mother’s diet: [A] Trans fat (TFA) diet; [B] MSG + TFA diet; [C] ASP + TFA diet; [D] ASP + MSG + TFA diet. Whilst dietary MSG significantly increased hepatic triglyceride and serum leptin levels in TFA-fed mice, the combination of ASP + MSG promoted the highest increase in visceral adipose tissue deposition, serum free fatty acids, fasting blood glucose, HOMA-IR, total cholesterol and TNFα levels. Microarray analysis of significant differentially expressed genes (DEGs) showed a reduction in hepatic and adipose tissue PPARGC1a expression concomitant with changes in PPARGC1a-related functional networks including PPARα, δ and γ. We identified 73 DEGs common to both adipose and liver which were upregulated by ASP + MSG in Trans fat-fed mice; and an additional 51 common DEGs which were downregulated. The combination of ASP and MSG may significantly alter adiposity, glucose homeostasis, hepatic and adipose tissue gene expression in TFA-fed C57Bl/6 J mice.
CLN3 disease is a fatal neurodegenerative disorder affecting children. Hallmarks include brain atrophy, accelerated neuronal apoptosis, and ceramide elevation. Treatment regimens are supportive, highlighting the importance of novel, disease-modifying drugs. Flupirtine and its new allyl carbamate derivative (compound 6) confer neuroprotective effects in CLN3-deficient cells. This study lays the groundwork for investigating beneficial effects in Cln3Δex7/8 mice. WT/Cln3Δex7/8 mice received flupirtine/compound 6/vehicle for 14 weeks. Short-term effect of flupirtine or compound 6 was tested using a battery of behavioral testing. For flupirtine, gene expression profiles, astrogliosis, and neuronal cell counts were determined. Flupirtine improved neurobehavioral parameters in open field, pole climbing, and Morris water maze tests in Cln3Δex7/8 mice. Several anti-apoptotic markers and ceramide synthesis/degradation enzymes expression was dysregulated in Cln3Δex7/8 mice. Flupirtine reduced astrogliosis in hippocampus and motor cortex of male and female Cln3Δex7/8 mice. Flupirtine increased neuronal cell counts in male mice. The newly synthesized compound 6 showed promising results in open field and pole climbing. In conclusion, flupirtine improved behavioral, neuropathological and biochemical parameters in Cln3Δex7/8 mice, paving the way for potential therapies for CLN3 disease.
Neuronal ceroid lipofuscinoses (NCLs) are a group of autosomal recessive neurogenetic disorders caused by mutations in 14 different genes. CLN6 disease manifests as variant late-infantile NCL (vLINCL) or as an adult variant. In childhood, symptoms include speech delay, vision loss, cognitive and motor decline, seizures, and early death. An in-depth characterization of a naturally occurring Cln6 mutant mouse (Cln6nclf) is presented, with implications for translational research. The expanded phenotype provides data showing early death, vision loss, and motor deficits in male and female Cln6nclf mice. Diminished visual acuity in Cln6nclf mice was noted at 28 weeks of age, but the pathological loss of retinal layers began as early as 2 weeks or postnatal day 14 (P14). Apoptosis was confirmed by TUNEL staining in the Cln6nclf mouse brain at P8 and in the retina at P12. A peak in glial fibrillary acidic protein (GFAP) expression was established as a normal developmental phenomenon in the wild-type and Cln6nclf mouse brain cerebellum and the CA2–CA3 regions of the hippocampus at P8. In Cln6nclf mice, GFAP levels were elevated at P12 in the cerebellum and hippocampus. In the retina, a developmental peak in gliosis was absent, with increased astrogliosis noted at P6 and P8 in female and male Cln6nclf mice, respectively. This highlights the lack of a sex-dependent response in wild-type mice. These novel data position the Cln6nclf mouse model as a useful tool for screening potential therapeutics for human CLN6 disease.
Neuronal ceroid lipofuscinosis type 6 (CLN6) is a fatal, autosomal recessive neurodegenerative disorder characterized by cognitive/motor impairment, vision loss, as well as neuronal loss and gliosis in the brain, and premature death. Onset typically occurs in childhood. No approved pharmacological treatments exist that halt or reverse disease progression. A novel flupirtine benzyl carbamate was orally administered to male and female Cln6nclf mice from 4 to 28 weeks of age to evaluate its neuroprotective and antispastic effects. Drug treatment produced significant, sex-dependent phenotypic improvements. Treated mice of both sexes exhibited reduced hindlimb spasticity, but only treated males demonstrated diminution in locomotor hyperactivity and recovery of visuospatial performance. In the brains of male and female Cln6nclf mice, flupirtine benzyl carbamate significantly decreased astrocytosis, microgliosis and mitochondrial ATP synthase subunit C (SCMAS) accumulation, increased neuronal marker expression and reduced the number of TUNEL-positive cells. The treatment failed to rescue photoreceptor loss or clear retinal SCMAS storage. These outcomes result in distinct sex-specific differences in neuronal vulnerability and drug responsiveness. Overall, these findings demonstrate that flupirtine benzyl carbamate diminishes key motor, visual and pathological deficits in CLN6 disease, highlighting its promise as a potential disease-modifying therapy for CLN6 in humans despite sex-specific differences.
Background: Children presenting with progressive gait abnormality may suffer from a genetic disorder. NDUFS1-related mitochondrial complex I deficiency is a rare disorder with highly variable phenotypes. Predominant axonal neuropathy without prominent systemic metabolic dysfunction is unusual. Expanding reports of such presentations is important for accurate diagnosis. Case presentation: A young adolescent boy with non-consanguineous parents presented with an atypical and severe axonal sensorimotor polyneuropathy. His metabolic workup was negative. Molecular genetic analysis uncovered a rare form of mitochondrial complex I deficiency due to compound heterozygous variants of the NDUFS1 gene. Conclusions: This case highlights a rare and atypical presentation associated with two NDUFS1 variants, one previously annotated as variant of uncertain significance in ClinVar. The other is novel. This expands the phenotypic and genetic spectrum linked to NDUFS1 -related disorders.